src/main/java/net/pterodactylus/sone/core/SoneInserter.java

   1 /*
   2  * Sone - SoneInserter.java - Copyright © 2010–2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.sone.core;
  19
  20 import static com.google.common.base.Optional.absent;
  21 import static com.google.common.base.Optional.of;
  22 import static com.google.common.base.Preconditions.checkArgument;
  23 import static java.lang.System.currentTimeMillis;
  24 import static net.pterodactylus.sone.data.Album.NOT_EMPTY;
  25
  26 import java.io.InputStreamReader;
  27 import java.io.StringWriter;
  28 import java.nio.charset.Charset;
  29 import java.util.HashMap;
  30 import java.util.HashSet;
  31 import java.util.Map;
  32 import java.util.logging.Level;
  33 import java.util.logging.Logger;
  34
  35 import net.pterodactylus.sone.core.event.SoneInsertAbortedEvent;
  36 import net.pterodactylus.sone.core.event.SoneInsertedEvent;
  37 import net.pterodactylus.sone.core.event.SoneInsertingEvent;
  38 import net.pterodactylus.sone.data.Album;
  39 import net.pterodactylus.sone.data.Post;
  40 import net.pterodactylus.sone.data.Reply;
  41 import net.pterodactylus.sone.data.Sone;
  42 import net.pterodactylus.sone.data.Sone.SoneStatus;
  43 import net.pterodactylus.sone.freenet.StringBucket;
  44 import net.pterodactylus.sone.main.SonePlugin;
  45 import net.pterodactylus.util.io.Closer;
  46 import net.pterodactylus.util.logging.Logging;
  47 import net.pterodactylus.util.service.AbstractService;
  48 import net.pterodactylus.util.template.HtmlFilter;
  49 import net.pterodactylus.util.template.ReflectionAccessor;
  50 import net.pterodactylus.util.template.Template;
  51 import net.pterodactylus.util.template.TemplateContext;
  52 import net.pterodactylus.util.template.TemplateContextFactory;
  53 import net.pterodactylus.util.template.TemplateException;
  54 import net.pterodactylus.util.template.TemplateParser;
  55 import net.pterodactylus.util.template.XmlFilter;
  56
  57 import com.google.common.base.Optional;
  58 import com.google.common.collect.FluentIterable;
  59 import com.google.common.collect.Ordering;
  60 import com.google.common.eventbus.EventBus;
  61
  62 import freenet.client.async.ManifestElement;
  63 import freenet.keys.FreenetURI;
  64
  65 /**
  66  * A Sone inserter is responsible for inserting a Sone if it has changed.
  67  *
  68  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  69  */
  70 public class SoneInserter extends AbstractService {
  71
  72         /** The logger. */
  73         private static final Logger logger = Logging.getLogger(SoneInserter.class);
  74
  75         /** The insertion delay (in seconds). */
  76         private static volatile int insertionDelay = 60;
  77
  78         /** The template factory used to create the templates. */
  79         private static final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  80
  81         static {
  82                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  83                 templateContextFactory.addFilter("xml", new XmlFilter());
  84                 templateContextFactory.addFilter("html", new HtmlFilter());
  85         }
  86
  87         /** The UTF-8 charset. */
  88         private static final Charset utf8Charset = Charset.forName("UTF-8");
  89
  90         /** The core. */
  91         private final Core core;
  92
  93         /** The event bus. */
  94         private final EventBus eventBus;
  95
  96         /** The Freenet interface. */
  97         private final FreenetInterface freenetInterface;
  98
  99         /** The Sone to insert. */
 100         private volatile Sone sone;
 101
 102         /** The fingerprint of the last insert. */
 103         private volatile String lastInsertFingerprint;
 104
 105         /**
 106          * Creates a new Sone inserter.
 107          *
 108          * @param core
 109          *            The core
 110          * @param eventBus
 111          *            The event bus
 112          * @param freenetInterface
 113          *            The freenet interface
 114          * @param sone
 115          *            The Sone to insert
 116          */
 117         public SoneInserter(Core core, EventBus eventBus, FreenetInterface freenetInterface, Sone sone) {
 118                 super("Sone Inserter for “" + sone.getName() + "”", false);
 119                 this.core = core;
 120                 this.eventBus = eventBus;
 121                 this.freenetInterface = freenetInterface;
 122                 this.sone = sone;
 123         }
 124
 125         //
 126         // ACCESSORS
 127         //
 128
 129         /**
 130          * Sets the Sone to insert.
 131          *
 132          * @param sone
 133          *              The Sone to insert
 134          * @return This Sone inserter
 135          */
 136         public SoneInserter setSone(Sone sone) {
 137                 checkArgument((this.sone == null) || sone.equals(this.sone), "Sone to insert can not be set to a different Sone");
 138                 this.sone = sone;
 139                 return this;
 140         }
 141
 142         /**
 143          * Changes the insertion delay, i.e. the time the Sone inserter waits after it
 144          * has noticed a Sone modification before it starts the insert.
 145          *
 146          * @param insertionDelay
 147          *            The insertion delay (in seconds)
 148          */
 149         public static void setInsertionDelay(int insertionDelay) {
 150                 SoneInserter.insertionDelay = insertionDelay;
 151         }
 152
 153         /**
 154          * Returns the fingerprint of the last insert.
 155          *
 156          * @return The fingerprint of the last insert
 157          */
 158         public String getLastInsertFingerprint() {
 159                 return lastInsertFingerprint;
 160         }
 161
 162         /**
 163          * Sets the fingerprint of the last insert.
 164          *
 165          * @param lastInsertFingerprint
 166          *            The fingerprint of the last insert
 167          */
 168         public void setLastInsertFingerprint(String lastInsertFingerprint) {
 169                 this.lastInsertFingerprint = lastInsertFingerprint;
 170         }
 171
 172         /**
 173          * Returns whether the Sone inserter has detected a modification of the
 174          * Sone.
 175          *
 176          * @return {@code true} if the Sone has been modified, {@code false}
 177          *         otherwise
 178          */
 179         public boolean isModified() {
 180                 return !lastInsertFingerprint.equals(sone.getFingerprint());
 181         }
 182
 183         //
 184         // SERVICE METHODS
 185         //
 186
 187         /**
 188          * {@inheritDoc}
 189          */
 190         @Override
 191         protected void serviceRun() {
 192                 Optional<Long> lastModificationTime = absent();
 193                 String lastInsertedFingerprint = lastInsertFingerprint;
 194                 String lastFingerprint = "";
 195                 while (!shouldStop()) {
 196                         try {
 197                                 /* check every second. */
 198                                 sleep(1000);
 199
 200                                 /* don’t insert locked Sones. */
 201                                 Sone sone = this.sone;
 202                                 if (core.isLocked(sone)) {
 203                                         /* trigger redetection when the Sone is unlocked. */
 204                                         lastFingerprint = "";
 205                                         lastModificationTime = absent();
 206                                         continue;
 207                                 }
 208
 209                                 boolean insertSoneNow = false;
 210                                 synchronized (sone) {
 211                                         String fingerprint = sone.getFingerprint();
 212                                         if (!fingerprint.equals(lastFingerprint)) {
 213                                                 if (fingerprint.equals(lastInsertedFingerprint)) {
 214                                                         lastModificationTime = absent();
 215                                                         logger.log(Level.FINE, String.format("Sone %s has been reverted to last insert state.", sone));
 216                                                 } else {
 217                                                         lastModificationTime = of(currentTimeMillis());
 218                                                         logger.log(Level.FINE, String.format("Sone %s has been modified, waiting %d seconds before inserting.", sone.getName(), insertionDelay));
 219                                                 }
 220                                                 lastFingerprint = fingerprint;
 221                                         }
 222                                         if (lastModificationTime.isPresent() && ((currentTimeMillis() - lastModificationTime.get()) > (insertionDelay * 1000))) {
 223                                                 lastInsertedFingerprint = fingerprint;
 224                                                 insertSoneNow = true;
 225                                         }
 226                                 }
 227
 228                                 if (insertSoneNow) {
 229                                         InsertInformation insertInformation = new InsertInformation(sone);
 230                                         logger.log(Level.INFO, String.format("Inserting Sone “%s”…", sone.getName()));
 231
 232                                         boolean success = false;
 233                                         try {
 234                                                 sone.setStatus(SoneStatus.inserting);
 235                                                 long insertTime = currentTimeMillis();
 236                                                 insertInformation.setTime(insertTime);
 237                                                 eventBus.post(new SoneInsertingEvent(sone));
 238                                                 FreenetURI finalUri = freenetInterface.insertDirectory(insertInformation.getInsertUri(), insertInformation.generateManifestEntries(), "index.html");
 239                                                 eventBus.post(new SoneInsertedEvent(sone, currentTimeMillis() - insertTime));
 240                                                 /* at this point we might already be stopped. */
 241                                                 if (shouldStop()) {
 242                                                         /* if so, bail out, don’t change anything. */
 243                                                         break;
 244                                                 }
 245                                                 sone.setTime(insertTime);
 246                                                 sone.setLatestEdition(finalUri.getEdition());
 247                                                 core.touchConfiguration();
 248                                                 success = true;
 249                                                 logger.log(Level.INFO, String.format("Inserted Sone “%s” at %s.", sone.getName(), finalUri));
 250                                         } catch (SoneException se1) {
 251                                                 eventBus.post(new SoneInsertAbortedEvent(sone, se1));
 252                                                 logger.log(Level.WARNING, String.format("Could not insert Sone “%s”!", sone.getName()), se1);
 253                                         } finally {
 254                                                 sone.setStatus(SoneStatus.idle);
 255                                         }
 256
 257                                         /*
 258                                          * reset modification counter if Sone has not been modified
 259                                          * while it was inserted.
 260                                          */
 261                                         if (success) {
 262                                                 synchronized (sone) {
 263                                                         if (insertInformation.getFingerprint().equals(sone.getFingerprint())) {
 264                                                                 logger.log(Level.FINE, String.format("Sone “%s” was not modified further, resetting counter…", sone));
 265                                                                 lastModificationTime = absent();
 266                                                                 lastInsertFingerprint = insertInformation.getFingerprint();
 267                                                                 core.touchConfiguration();
 268                                                         }
 269                                                 }
 270                                         }
 271                                 }
 272                         } catch (Throwable t1) {
 273                                 logger.log(Level.SEVERE, "SoneInserter threw an Exception!", t1);
 274                         }
 275                 }
 276         }
 277
 278         /**
 279          * Container for information that are required to insert a Sone. This
 280          * container merely exists to copy all relevant data without holding a lock
 281          * on the {@link Sone} object for too long.
 282          *
 283          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 284          */
 285         private class InsertInformation {
 286
 287                 private final String fingerprint;
 288
 289                 /** All properties of the Sone, copied for thread safety. */
 290                 private final Map<String, Object> soneProperties = new HashMap<String, Object>();
 291
 292                 /**
 293                  * Creates a new insert information container.
 294                  *
 295                  * @param sone
 296                  *            The sone to insert
 297                  */
 298                 public InsertInformation(Sone sone) {
 299                         this.fingerprint = sone.getFingerprint();
 300                         soneProperties.put("id", sone.getId());
 301                         soneProperties.put("name", sone.getName());
 302                         soneProperties.put("time", sone.getTime());
 303                         soneProperties.put("requestUri", sone.getRequestUri());
 304                         soneProperties.put("insertUri", sone.getInsertUri());
 305                         soneProperties.put("profile", sone.getProfile());
 306                         soneProperties.put("posts", Ordering.from(Post.TIME_COMPARATOR).sortedCopy(sone.getPosts()));
 307                         soneProperties.put("replies", Ordering.from(Reply.TIME_COMPARATOR).reverse().sortedCopy(sone.getReplies()));
 308                         soneProperties.put("likedPostIds", new HashSet<String>(sone.getLikedPostIds()));
 309                         soneProperties.put("likedReplyIds", new HashSet<String>(sone.getLikedReplyIds()));
 310                         soneProperties.put("albums", FluentIterable.from(sone.getRootAlbum().getAlbums()).transformAndConcat(Album.FLATTENER).filter(NOT_EMPTY).toList());
 311                 }
 312
 313                 //
 314                 // ACCESSORS
 315                 //
 316
 317                 private String getFingerprint() {
 318                         return fingerprint;
 319                 }
 320
 321                 /**
 322                  * Returns the insert URI of the Sone.
 323                  *
 324                  * @return The insert URI of the Sone
 325                  */
 326                 public FreenetURI getInsertUri() {
 327                         return (FreenetURI) soneProperties.get("insertUri");
 328                 }
 329
 330                 /**
 331                  * Sets the time of the Sone at the time of the insert.
 332                  *
 333                  * @param time
 334                  *            The time of the Sone
 335                  */
 336                 public void setTime(long time) {
 337                         soneProperties.put("time", time);
 338                 }
 339
 340                 //
 341                 // ACTIONS
 342                 //
 343
 344                 /**
 345                  * Generates all manifest entries required to insert this Sone.
 346                  *
 347                  * @return The manifest entries for the Sone insert
 348                  */
 349                 public HashMap<String, Object> generateManifestEntries() {
 350                         HashMap<String, Object> manifestEntries = new HashMap<String, Object>();
 351
 352                         /* first, create an index.html. */
 353                         manifestEntries.put("index.html", createManifestElement("index.html", "text/html; charset=utf-8", "/templates/insert/index.html"));
 354
 355                         /* now, store the sone. */
 356                         manifestEntries.put("sone.xml", createManifestElement("sone.xml", "text/xml; charset=utf-8", "/templates/insert/sone.xml"));
 357
 358                         return manifestEntries;
 359                 }
 360
 361                 //
 362                 // PRIVATE METHODS
 363                 //
 364
 365                 /**
 366                  * Creates a new manifest element.
 367                  *
 368                  * @param name
 369                  *            The name of the file
 370                  * @param contentType
 371                  *            The content type of the file
 372                  * @param templateName
 373                  *            The name of the template to render
 374                  * @return The manifest element
 375                  */
 376                 @SuppressWarnings("synthetic-access")
 377                 private ManifestElement createManifestElement(String name, String contentType, String templateName) {
 378                         InputStreamReader templateInputStreamReader = null;
 379                         Template template;
 380                         try {
 381                                 templateInputStreamReader = new InputStreamReader(getClass().getResourceAsStream(templateName), utf8Charset);
 382                                 template = TemplateParser.parse(templateInputStreamReader);
 383                         } catch (TemplateException te1) {
 384                                 logger.log(Level.SEVERE, String.format("Could not parse template “%s”!", templateName), te1);
 385                                 return null;
 386                         } finally {
 387                                 Closer.close(templateInputStreamReader);
 388                         }
 389
 390                         TemplateContext templateContext = templateContextFactory.createTemplateContext();
 391                         templateContext.set("core", core);
 392                         templateContext.set("currentSone", soneProperties);
 393                         templateContext.set("currentEdition", core.getUpdateChecker().getLatestEdition());
 394                         templateContext.set("version", SonePlugin.VERSION);
 395                         StringWriter writer = new StringWriter();
 396                         StringBucket bucket = null;
 397                         try {
 398                                 template.render(templateContext, writer);
 399                                 bucket = new StringBucket(writer.toString(), utf8Charset);
 400                                 return new ManifestElement(name, bucket, contentType, bucket.size());
 401                         } catch (TemplateException te1) {
 402                                 logger.log(Level.SEVERE, String.format("Could not render template “%s”!", templateName), te1);
 403                                 return null;
 404                         } finally {
 405                                 Closer.close(writer);
 406                                 if (bucket != null) {
 407                                         bucket.free();
 408                                 }
 409                         }
 410                 }
 411
 412         }
 413
 414 }